The invention relates to a pivoting bearing for two connecting rods in at least one reciprocating piston of an internal combustion engine having two crankshafts which are driven via the reciprocating piston and the connecting rods.
An internal combustion engine is known (US 2010/0077984 A1), in which two parallel crankshafts are driven by means of a reciprocating piston and using two connecting rods. The connecting rods are connected to bearing sections of the pistons in an articulated manner via connecting rod eyes and gudgeon pins.
A similar internal combustion engine is apparent from EP 2 426 336 A2. However, the connecting rod eyes are attached on pivoting bearings such that they can be moved pivotably via gudgeon pins. Said pivoting bearings are mounted in bores of the reciprocating piston such that they can be rotated relative to the latter.
It is an object of the invention to design a pivoting bearing in a piston for connecting rod eyes of connecting rods, which pivoting bearing is distinguished by a functional construction. It should also be ensured here, however, that bearing points of the pivoting bearing, above all between connecting rod eyes and connecting rod eye pins, are supplied satisfactorily with lubricant.
According to the invention, said object is achieved by a pivoting bearing for two connecting rods in at least one reciprocating piston of an internal combustion engine having two crankshafts which are driven via the reciprocating piston and the connecting rods, the pivoting bearing being received by piston bores of the piston and having pin bores for mounting gudgeon pins for gudgeon pin eyes of the connecting rods. The pivoting bearing has radial bearing regions which are provided with the pin bores, are arranged on both sides of a center longitudinal axis of the reciprocating piston, and delimit the gudgeon pin eyes in a manner which forms an intermediate space. The bearing regions of the pivoting bearing are configured as cylinder bodies with a cup-like cross section, of which each cylinder body has a base wall and a bearing ring shell. The base walls of the two cylinder bodies extend at a spacing from one another, and the bearing ring shells which surround the base walls are guided away from the base walls in opposite directions. A plurality of connecting stubs run between the base walls in such a way that two connecting stubs are arranged on a side of the pivoting bearing, which side faces a piston crown, and extend at a relatively small spacing from ring sections of the gudgeon pin eyes, and in such a way that, moreover, the connecting stubs and the ring sections have measures for lubricating connecting rod bearings of the connecting rods.
The advantages which are mainly achieved by way of the invention can be seen in that the bearing regions of the pivoting bearings are configured as cylinder bodies with a cup-like cross section, of which each cylinder body has a base wall and a bearing ring shell, which base walls of the two cylinder bodies extend at a spacing from one another, the bearing ring shells which surround the base walls being guided away from the base walls in opposite directions, and a plurality of connecting stubs running between the base walls in such a way that two connecting stubs are arranged on a side of the pivoting bearing, which side faces a piston crown, and extend at a relatively small spacing from ring sections of the connecting rod eyes, and in such a way that, moreover, the connecting stubs and the ring sections have measures for lubricating the connecting rod bearings.
The successful and easily realizable construction and the measures for lubricating the connecting rod bearings are to be highlighted in the pivoting bearing. The fact that firstly the connecting stubs are of annular configuration and are adapted to the shape profile of the ring sections of the gudgeon pin eyes, and secondly that through openings, which face one another in the connecting stubs and the ring sections for the access of lubricant of the lubrication, are arranged in bearing points between the pin bores of the connecting rods and the gudgeon pins, achieve the advantages in an exemplary manner.
It is exemplary firstly that the through openings have an oval shape in the connecting stubs and a circular shape in the ring sections, and that secondly the through openings of the connecting stubs and the ring sections have common center longitudinal planes. It is of technically high importance that the lubricant of the lubrication firstly passes by way of roving particles of aerosol-containing gases in a crankcase of the internal combustion engine and secondly by way of devices of the crankshafts and the connecting rods into the intermediate space and/or to the through openings. It is ingenious that the devices are formed firstly by way of recesses which are arranged on opposite longitudinal sides of the crank pin eyes and secondly by way of guiding apparatuses which extend between the crank pin eyes and the gudgeon pin eyes, via which guiding apparatuses lubricants of the lubrication are moved into the intermediate space and/or the through openings. In a simple way, said devices can be formed by way of longitudinal grooves on the longitudinal sides of the connecting rod shanks of the connecting rods, which longitudinal grooves extend between the crank pin eyes and the gudgeon pin eyes. Finally, however, there is also the possibility that the devices are formed by way of longitudinal bores in the connecting rod shanks of the connecting rods between the crank pin eyes and the gudgeon pin eyes.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.